Separable electrical connectors

ABSTRACT

Compound copulatory separable connector with integrated arccontrolling means adapting it for safe use as a load-break and load-make switch.

[ 51 June 6,1972

[541 SEPARABLE ELECTRICAL w 4 H m 2 2,231,576 2/1941 2,363,295 11/1944 Cotter...... 2,267,399 12/1941 Farrer et 3,297,848 1/1967 Picard et CONNECTORS [72] Inventor: Robert D. Ball, Tucker, Ga.

[73] Assignee: Kearney-National Inc., Atlanta, Ga. FOREIGN PATENTS OR APPLICA'HONS {22] Filed: Feb. 2, 1970 [21] Appl. No.: 7,942

799,503 8/1958 Great Britain.........................339/1l1 Primary Examiner-Richard E. Moore Attorney-Paul M. Denk ABSTRACT [52] US. [51] Int. {58] Field of Compound copulatory separable connector with integrated arc-controlling means adapting it for safe use as a load-break and load-make switch.

References Cited 16 Claims, 8 Drawing Figures UNITED STATES PATENTS Link.............

SEPARABLE ELECTRICAL CONNECTORS The invention relates to separable connectors of the general type suitable for use in making and breaking the connection between a high voltage electrical main and apparatus energized thereby, such as the transformers utilized in so-called URD systems. A URD" system is described in an article by A.G. Dahl, published in the Sept. 5, 1966 issue of Electrical World at pages 39, et seq. In the system there described, the primaries of unit residential transformers are equipped with terminals which form the stationary portion of copulatory connectors, the removable portion of which is permanently connected to a cable forming a part of an 8.32/4.8 kv. distribution loop or leg. In such installations, the removable portion of the connector may be manually disconnected from the stationary portion thereof to serve the purpose of a load-break switch, or, vice versa, the removable portion joined with the stationary portion to serve the purpose of load make switch, but a serious hazard is involved when a disconnected removable'portion is reconnected with the stationary portion while a fault (such as an unexpected ground fault) exists somewhere on the load side of the connector. The hazard is multiplied with each disconnection and reconnection of separable connector portions of the character currently conventional (up to kv.) which have the conductive member of the separable portion equipped with a follower made of arc suppressing, but substantially non-conductive, material. Such a follower is mounted at the free end of the separable parts conductive member and leads the latter in circuit-making or reclosing" operation, but trails the conductive member in the circuit-interrupting operation. In the normal course of manipulating the connector in an energized high voltage circuit, some are is always drawn at the time the contacts approach toward or separate from each other, and the higher the voltage, the greater arc; carbonization of non-conductive parts in the path of the arc occurs more or less in proportion to the magnitude of the voltage, and the carbon deposit increases with each operation of circuit-making or breaking until, after a relatively few such operations, the arc is likely to flash over the follower. If, on reclosing the circuit, a fault exists on theload side of the separable connector, it is not unknown that one or the other of the separable connectors may explode, spraying flame and hot metal particles about the environs. As a precautionary measure, the industry has adopted a so-called Used Parts Fault Close test which such separable connectors must pass. That test requires that ten normal.load-make/Ioad-break operations be effected at rated voltageto condition the parts for one closing under fault conditions without malfunction.

One object of the invention is to provide a separable connector for the purpose aforesaid, which may be repeatedly manipulated to open and close load current circuits even at I voltages in excess of 15 kv., followed by closing under fault conditions without malfunction.

Another and more specific object of the invention is to provide a separable connector of the type aforesaid with internal instrumentalities for so improving the arc-quenching process that the connector is qualified for higher voltage applications than 15 kv.

The present invention contemplates that the stationary portion of such a separable connector be provided, within a maleconfigurated insulating member, witha female-configurated conductive part in permanent connection with the apparatus which is to be energized; and that the removable portion of the connector be provided, within a female-configurated insulating member complementary with the aforesaid male-configurated insulating member with a male-configurated conductive part which is complemental at one end with the aforesaid female-contigurated conductive part, and which, at its opposite end, is permanently connected with a flexible or semi-flexible insulated conductor which, in the illustrative URD" environment aforesaid, would normally be a cable forming a part of a loop or leg of a distribution circuit for energizing the primary of a transformer. A further feature of the invention is the provision on the male and/or female configurated conductive parts of means for diverting any are drawn (in the process of making or breaking the connection) away from the areas thereof which will be in contact when the removable portion of the connector is in its final circuit closing position, and thereby to minimize the evolution of hot metal particles from the areas of arc impingement.

The invention further contemplates that the stationary portion of the connector be equipped internally, between the terminus of the female conductive part therein and the free end of the male insulating member thereof, with a composite capsular structure formed of non-carbon evolving, nontracking, arc-extinguishing (or at least arc-resisting) electrical insulating material which is subdivided into axially aligned chambers separated one from the other by baffles, but communicating with each other through axially aligned openings in the baffles which together provide an open channel for the insertion of the male-configurated conductive part on the movable portion of the connector. The composite capsular structure is preferably formed of two identical halves which interfit to form an axially split open-ended capsule enclosing the chambers and other parts confined therein; and after the halves have been interfitted with each other about the contained parts, the capsule halves are bound together by winding a high tensile insulating material, such as fiberglass, circumferentially about them, thereby the better to withstand forces generated internally thereof which might otherwise rupture the capsule. The resultant composite capsular structure is preferably covered with a layer of semi-conductive rubber, flexible paint or the like, which is in permanent contact with the female conductive part. The several chambers in the capsular structure mentioned preferably accommodate paired segments of arc-suppressing dielectric material, which are resiliently biased toward each other, but yieldable to permit the insertion of the aforesaid male-configurated conductive part, yet when the said conductive part is removed from between 'a pair of such segments, the segments of the justvacated pair are immediately biased toward each other in pinching relation with any are which may then exist between those paired segments thereby: to divert and elongate any are which persists; expose the arc to arc-suppressing material having an accessible surface area which is relatively large, for an empiric example, the surface area (flat and arcuate) of the several segments is preferably about three times the surface area of that portion of the male-configurated conductive part which is embraced by the several chambers at the time a disconnect arc is drawn; and to assure extinguishment of that are before the free end of the male conductive element on the removable portion of the connector is free of the end of the male insulating member on the stationary portion of the connector.

One embodiment of the invention is illustrated in the ac- I companying drawings, in which:

FIG. 1 is a perspective view of a connector constructed in accordance with the present invention the stationary and removable portions being shown in separated relationship, but positioned for movement into connected relationship;

FIG. 2 is a view inside elevation showing, in assembled relationship, the stationary and removable portions of FIG. 1, part being in section to show the relationship of internal instrumentalities when the stationary and movable portions have been telescoped into conducting relationship;

FIG. 3 is a view in side elevation, with portions in section, of the encapsulated insides of the stationary connector portion;

FIG. 4 is a sectional view taken at the location of line 44 of FIG. 3, but with the male configurated conductive part and showing the internal arrangement of arc-pinching and quenching instrumentalities;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 3 to show the relationship of the conductive members in the stationary portion of the connector;

FIG. 6 is a perspective view of an arc-quenching segment, three pairs of which are shown in FIG. 2;

FIG. 7 is a perspective view of a half-liner forming a part of the insides shown in FIG. 3; and

FIG. 8 is a perspective view of an alternative form of arc diverter for use on the female-configurated conductive pan of the connectors stationary portion.

As shown in FIG. 1, the separable portions of the connector are positioned in aligned relationship from which axial movement of the removable portion 1 into telescoping relationship with the stationary portion 2 will complete an electrical circuit between a male conductive part within portion 1 and a female conductive part .within stationary portion 2. As shown in FIG. 1, the removable portion 1 is in the form of an elbow, and is integrally connected with a semi-conductive-rubber-covered cable 3, about which a shielding wire is wound in accordance with the usual practice. The stationary portion 2 of the connector is equipped with a flange 4 for mechanically mounting it upon an electrical apparatus, such as a transformer, and a stud 5 for electrically connecting it with the instrumentalities to be energized within the apparatus. As is customary with separable connectors of this general type, where, as shown, the stationary portion has a male-formed non-conductive probe of shape and size to mate with a female-shaped nonconductive member within the removable portion 1 the electrically conductive parts in each of portions 1 and 2 being arranged within the respective non-conductive members in a manner to be now described in connection with FIG. 2.

The removable portion 1 in the embodiment shown has an exterior sheath 6 of semi-conductive rubber, which is relatively rigid and hard, within which there is a body 7 of rubber, having substantially higher dielectric strength than does the sheath 6, and which is more resilient than the sheath 6. The interior of the body 7 is hollow to provide a cavity with a conoidal interior delineated by lines 8 in FIG. 2.

Extending axially of the conoidal cavity within body 7 is an electrically conductive probe 9, having a tip 10, and securely mounted at its other end in a conventional manner at the turn of portion 1. The tip 10 of probe 9 is preferably provided with an arc-resisting surface, such as by being made of a tungsten ring, silver-soldered on the body of probe 9, or, alternatively, by being brazed with a tungsten copper alloy.

The stationary portion 2 of the connector has an exterior conoidal shield 11 of comparable high dielectric strength, resilient rubber .to that of body 7. The shape and size of the male-formed shield 11 is such as to be complemental with the interior of body 7 when the separable connector portions are completely telescoped, as shown in FIG. 2, so that the conductive parts of each of the separable portions is in current transmitting relationship with those of the other. Axially centered I within shield 11, there is a sub-assembly of instrumentalities,

hereinafter termed the insides, all contained within a capsule 12 shown in FIG. 3. The capsule 12 includes two identical half-liners 13, shown in FIG. 7. The half-liners 13 are preferably molded or cast of a plastic material which is at least arc-resistant, and preferably has arc-suppressing qualities. Each half-liner 13 is divided into a plurality of compartments by cross-baffles 14, 15, and 16, together with end plugs 17 and 18. Baffles 15 and 16 are provided with notches 19 and 20, whose diameter is about 0.025 to 0.035 inch greater than the diameter of conductive probe 9, and the same applies to channel 21 in end plug 18. In contrast, however, notch 22 in baffle 14 preferably has a diameter of between 0.300 and 0.400 inch in excess of the diameter of conductive probe 9. The three chambers defined between the inside end wall of plug 18 and baffle 16, between baffle 16 and baffle 15, and between baffle 15 and baffle 14, are each designed to accommodate an arcpinching clapper of the character shown in FIG. 6, that is to say, that in the capsular assembly of two such half-liners as that shown in FIG. 7, three pair of such arc-pinching clappers will be accommodated. Accordingly, each of the aforesaid chambers is equipped with a hollow pedestal 23, within which a clapper spring 24 is seated, and about which a clapper 25 is mounted.

Each half-liner, such as that shown in FIG. 7, is equipped with a longitudinally extending rabbet 26 along one side, and a complementary lip 27 along the other side. Comparable lips and rabbets are also preferably provided, respectively on the edges of the baffles at opposite sides of the notches 19, 20 and 22. The lipped and rabbeted structure just described not only assures that two such half-liners, when assembled together, will be accurately positioned with respect to each other, but that when the two joints are sealed with dielectric adhesive, the opportunity for arcs and are gases to pass between the assembled parts is minimized.

The end plug 28 of the half-liner shown in FIG. 7 is contoured and proportioned to mate with the external grooving and shouldering on a conductive element 29 later to be described in detail.

The clapper elements 25 are shown in detail in FIG. 6. Each is a molded segment of a material such as melamine, which, when exposed to an electric arc, evolves gases which tend to quench that arc. Each such clapper segment has a half-funnel mouth 30 which, in cooperation with the partner of its pair, guides the tip 10 of probe 9 between the pair of clapper segments mounted in a given one of the chambers separated by baffles 19 and 20, as the probe 9 moves from the disconnected position shown in FIG. 1 toward the connected position shown in FIG. 2. As mentioned previously, the several clapper seg ments are constantly biased toward each other by springs 24, the radially outer ends of which are received in a recess within the adjacent pedestal 23, while the radially inward ends of the spring are accommodated in a rebate 31, in the floor of socket 32, which accommodates a pedestal 23, and loosely interlocks the clapper element with the pedestal and spring.

Prior to assembling the pair of half-liners with each other, and about the paired clappers and their cooperating springs, the conductive element 29 must be inserted between the end plugs 28 of the respective half-liners. Once the several instrumentalities have been properly assembled within the companion half-liners, the lips and rabbets of the respective halfliners are coated with dielectric adhesive sealant of a type compatible vw'th the material of which the half-liners are made; and then each rabbet 26 of one half-liner is brought into interlocking relationship with a lip 27 of the other half-liner, thereby to encapsulate the current-conducting and arc-controlling instrumentalities of the insides for the stationary portion 2 of the separable connector. Having thus assembled and sealed the parts within the companion half-liners, the halfliners are firmly bound together, and this is preferably accomplished by applying to them a jacket 33 of filamentary material having high tensile strength and high dielectric strength. Fiberglass satisfies both requirements, and can be applied either in stranded form, or in the form of an embedment in plastic material having high dielectric strength. Regardless of the mode of application, the assembly of components comprising the aforesaid insides has a reinforcing integument 33, preferably composed of fiberglass strands wound helically about the assembled half-liners and embedded in plastic material which can be integrated with itself about the outside of the assembled half-liners and their contents. As previously indicated, the capsular structure may also have an outer integument 36 of semi-conductive rubber which may be molded in situ or preformed and applied as a boot but, in either event, the lower extremity of integument 36 is in permanent electrical contact with the conductive element 29 so that integument 36 is, throughout its length, at the same polarity as element 29.

To protect the conductive element 29 from damage by arcing and to minimize hot metal particles in the arc path, the inner end (i.e., the upper end as shown in FIG. 2) is either tungsten tipped or brazed with a tungsten copper alloy.

The aforesaid insides constitute an article of manufacture, which may be marketed, per se, to manufacturers of separable connectors, and by the latter embedded in the conoidal male-formed insulating probe, such as 11, which is appropriately mounted upon the apparatus to be energized and controlled through the separable connector.

While such insides may have any suitable form of conductive element permanently mounted therein, so as to be readily connectable in a permanent manner with the apparatus to be energized, it is preferred that the conductive element 29 forming a pan of such insides be female-shaped and biased in a direction tending to contract it. ln the form shown in FIG. 2, such a conductive element is provided by making at least the inner end of conductive element 29 hollow, slitting it axially in order to divide it circumferentially into a plurality of fingers 34, of which there are eight in the embodiment shown, and then providing a garter spring 35 in a manner such as to contract the extremities of fingers 34 toward each other. In the form shown in the drawing, the garter spring is accommodated in an exterior circumferential groove which may be produced by deforming the fingers so as to make an internally projecting circumferential ridge whose internal diameter is sufficiently less than the outside diameter of probe 9 that the fingers 34 will be wedged radially outward (against the tension of spring 35) when the probe 9 is inserted within them. Moreover, the inner periphery of the array of tungsten tipped extremities on the fingers 34 is preferably such that such extremities be out of contact with the probe 9 when the removable portion of the connector is fully seated in connecting position. The resultant female receptor is positioned in the chamber of the half-liners shown in FIG. 7 between baffle 14 and end plug 17, with the open end thereof addressed toward end plug 18, so that conductive probe 9, when inserted through channel 21 and between the paired arcpinching segments 25 in the several chambers delineated by baffles 19, and 22, is directed into the open mouth delineated by the ends of fingers 34; and when so inserted, the rounded tip 10 of the conductive probe wedges the fingers 34 outwardly against the tension of spring 35, thereby maintaining a tight electrical engagement between the female conductive receptor formed by the fingers 34 and the male conductive probe 9.

Having completed the assembly of all components of the insides" as just described, such insides may be utilized as a core about which the male-formed probe 11, of insulating material, may be molded in situ or preformed and applied. Preferably, the probe 11 is formed of relatively resilient rubber having high dielectric strength comparable to that util-- ized in molding the female insulating member 7. The exterior surface of the insulating probe 11 is conoidal in substantially exact mating relationship with the interior of member 7, so that when the tip 10 of probe 9 has passed beyond the garter spring 35, the members 7 and 11 will not only enclose the electrically live parts of the device,'but be hermetically sealed with each other.

Those skilled in the art will understand that the disclosed separable connector may be safely used as a disconnect switch (or as a reconnect switch even under fault conditions) without hazard of drawing an arc to the outside of the insulating probe 11. When, in the act of separating (or connecting) the removable portion 1 and the stationary portion 2, while under load, an arc is drawn between tip 10 of probe 9 and the tungsten tips of fingers 34, that are is short-lived unless, contrary to the usual practice, the action is halted before the separation (or connection) is completed, or at least substantially so. Any such are drawn between conductive probe 9 and receptor 29 is diverted from the areas which make contact under closed circuit conditions, and occurs between tip 10 and the tips of fingers 34; and is, as the separating action proceeds, subjected simultaneously to a plurality of arc-extinguishing influences, e.g., stretching, as the distance between tip 10 and tips of fingers 34 increases; pinching, as the successive pairs of clappers snap together behind the receding tip 10; rarefication of the atmosphere within capsule 12 (particularly if the separating action is fast enough, and the clearance between probe 9 and channel 21 small enough, that vacated space within the capsule 12 is increased at a greater rate than outside air can leak in between the outside of elastic probe 11 and elastic sheath 7, and then between probe 9 and channel 21); and evolution of arc-suppressing gases from the relatively large arc-accessible surface areas of the clappers 25, and the halfliners 13. On the other hand, when the removable portion of the connector is being moved into circuit closing position relative to the stationary portion, even under fault conditions, the interaction of: the several substantially isolated air gaps confined by the chambers between bafiles l4 and 15, 15 and 16, as well as baffle 16 and end plug 18, the bounding walls of which have arc-extinguishing qualities; the clappers 25 within said chambers which are made of arc suppressing material; the means, such as the tungsten tips on fingers 34 and probe 9, for diverting the arc away from the normal operating contact surface which might be melted by the arc; and the fiberglass winding about the exterior of the capsule which results not only in containing the are within a substructure which cannot be ruptured or exploded by the developed pressure (which is relieved by the expansion of the gases in the chambers formed around the clappers and contact 34), but also in confining the arc to zones where it can do no damage to the operating con tact surfaces and, in addition, expedite the extinguishment of the arc.

In lieu of providing the arc diverting means in the form of tungsten tips on fingers 34, or brazing said tips with tungsten copper alloy, the arc diverting means shown in FIG. 8 may be employed. The arc diverting means shown in FIG. 8 is a substantially dish-shaped conductive article of configuration such as to hug the walls of the cavity in which the fingers 34 are disposed. As shown, the dish-shaped article has a base 37 contoured to fit snugly against the rounded corners 38 of the aforesaid cavity, and thereby be disposed completely out of engagement with the tips of fingers 34. Centrally of the base 37, there is a circular hole 39, whose diameter is about 0.050 to 0.200 inch greater than the diameter of probe 9, or at least the portion thereof which must pass through hole 39 en route to and from contact-making relationship with the fingers 34. As shown, the dish-shaped article has at least two fingers 40, which are preferably contoured to mate with the interior of the cavity surrounding the fingers 34, and to make electrical contact with the conductive part 29 adjacent the bottom of the aforesaid cavity at or below the termination of the slits which delineate the fingers 34. Thus, the arrangement is such that when the probe 9 is being moved toward the circuit closing position shown in FlG. 2,- the initial are drawn will be between the tip 10 of the probe and the edges of hole 39. Accordingly, the arc is diverted away from the operating contact surfaces of fingers 34, and any pitting or melting of metal by the arc will occur adjacent hole 39 in the dish-shaped article which, as aforesaid, is in electrical contact with the conductive part 29 at a position remote from the surfaces of fingers 34 where normal operating conductive relationship is established with probe 9. The dish-shaped article shown in FIG. 8 may be made of copper, or other metal which need not necessarily be arc-resisting.

When the portions 1 and 2 of the connector are separated, the electrically conductive parts of each continue to be protected against all but deliberate contact with ambient objects. This is achieved by making the non-conductive skirt of portion 1 to extend axially beyond the tip 10 of conductive probe 9; and by locating conductive fingers 34 remote from the open end of capsule 12, with a plurality of clappers 25 intervening and arranged to mechanically obstruct the entry of objects from the outside.

While one complete embodiment of the invention has been disclosed in detail and some alternatives indicated, it is not to be understood that the invention is limited to the details of the illustrative embodiment. On the contrary, various features and subcombinations of features may be advantageously utilized alone or with appropriate alternatives to the environment indicated in the foregoing disclosure.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

l. A compound copulatory electrical connector for selectively connecting and disconnecting an energized electrical conductor with or from a load, said connector having separable portions, one of said portions having:

a. a conductive probe mechanically mounted thereto at one end and electrically connected with said conductor at the same end, said probe having a free end remote from said mounting;

b. a non-conductive open-ended receptor surrounding said probe in radially spaced relationship; the other of said portions having:

c. a non-conductive probe having a free end with an exterior surface shaped to mate with the interior of said receptor d. a conductive receptor having an interior surface shaped to mate with the exterior of said conductive probe (a) adjacent the free end' thereof, said interior surface being spaced from the free end of said non-conductive probe (c) by a distance substantially equal to but less than the length of said conductive probe (a) within said non-conductive receptor (b); and

e. a pair of arc-pinching elements mounted within said nonconductive probe (c) between said conductive receptor ((1) and the free end of said non-conductive probe (c), said arc-pinching elements being resiliently biased toward each other but free for forcible movement away from each other for a distance sufficient to accommodate said conductive probe (a) between them, said pair of arcpinching elements entering into contiguous closure to curtail arcing between said conductive probe and conductive receptor during insertion or withdrawal of said probe within said non-conductive probe.

2. The connector of claim 1 wherein said conductive receptor (d) has resilient fingers extending axially thereof adjacent said interior surface, and means biasing the free ends of said fingers radially inward.

3. The connector of claim 2 wherein said means is a garter spring.

4. The connector of claim 1 in which said arc-pinching elements are composed of arc-quenching material and have a relatively large arc-accessible surface area.

5. The connector of claim 1 in which said receptor and said arc-pinching elements are mounted in radially spaced relationship within a capsule composed of dielectric material which when exposed to an arc is non-carbon-evolving, nontracking, and arc-suppressing, and said capsule is embedded within said non-conductive probe (c).

6. The connector of claim 1 wherein said one of said portions is an elbow having a conductor extending through it.

7. The combination with an electrical connector part having a conoidal exterior insulating member, of an insides embedded in saidv member, comprising, a female-shaped conductive element, a capsule embracing at least part of said element, said capsule being composed of dielectric material which when exposed to an arc is non-carbon-evolving, non-tracking and arc-resistant, said capsule being internally subdivided into a plurality of chambers containing respectively:

i. at least part of said conductive element; and ii. paired arc-pinching elements radially biased toward each other, but free for movement into radially spaced relationship; said capsule having an axial channel open at the end thereof remote from said conductive element and extending through said chambers to accommodate movement of a conductive probe from the outer end of said member into contact with said element.

8. The combination of claim 7 in which adjacent ones of said chambers are separated by bafiles formed of arc-suppressing material.

9. The combination of claim 7 wherein said conductive element has a surface disposed for resilient contact with said probe, and means spaced from said surface but in conductive relation with said element for diverting, away from said surface, an are drawn between said probe and said element.

10. An insides for a male non-conductive part of a separable electrical connector, comprising, complemental half-liners of moldable arc-resistant material, said half-liners havin an axially extending valley at each end and a plurality o axially spaced partitions between said valleys, each partition having a central notch, said notches being axially aligned with each other and with said valleys, paired clappers of arc-quenching material confined between successive ones of said partitions, and means biasing the clappers of each pair toward each other.

11. The insides of claim 10 wherein said valleys at one end of said half-liners are interlocked with a female conductive member having axially extending fingers, resilient means for radially biasing said fingers, said paired clappers having halfconical recesses addressed toward each other with their bases addressed away from said female conductive part.

12. The insides of claim 10 having a female-configurated stationary contact at one end of said complemental half-liners.

13. The combination with the insides of claim 12 of a removable male-configurated conductive member proportioned to be accommodated in the notches and valleys of said complemental half-liners and to be accepted by said stationary contact.

14. The combination of claim 13 wherein the arc-accessible surface area of said clappers is substantially greater than the surface area of that portion of said male-configurated conductive member between said valleys and said stationary contact.

15. The connector of claim 1 wherein the free end of said conductive probe is formed at least in part of arc-resisting conductive material.

16. The connector of claim 1 wherein said non-conductive open-ended receptor extends axially beyond the free end of said conductive probe. 

1. A compound copulatory electrical connector for selectively connecting and disconnecting an energized electrical conductor with or from a load, said connector having separable portions, one of said portions having: a. a conductive probe mechanically mounted thereto at one end and electrically connected with said conductor at the same end, said probe having a free end remote from said mounting; b. a non-conductive open-ended receptor surrounding said probe in radially spaced relationship; the other of said portions having: c. a non-conductive probe having a free end with an exterior surface shaped to mate with the interior of said receptor (b); d. a conductive receptor having an interior surface shaped to mate with the exterior of said conductive probe (a) adjacent the free end thereof, said interior surface being spaced from the free end of said non-conductive probe (c) by a distance substantially equal to but less than the length of said conductive probe (a) within said non-conductive receptor (b); and e. a pair of arc-pinching elements mounted within said nonconductive probe (c) between said conductive receptor (d) and the free end of said non-conductive probe (c), said arcpinching elements being resiliently biased toward each other but free for forcible movement away from each other for a distance sufficient to accommodate said conductive probe (a) between them, said pair of arc-pinching elements entering into contiguous closure to curtail arcing between saId conductive probe and conductive receptor during insertion or withdrawal of said probe within said non-conductive probe.
 2. The connector of claim 1 wherein said conductive receptor (d) has resilient fingers extending axially thereof adjacent said interior surface, and means biasing the free ends of said fingers radially inward.
 3. The connector of claim 2 wherein said means is a garter spring.
 4. The connector of claim 1 in which said arc-pinching elements are composed of arc-quenching material and have a relatively large arc-accessible surface area.
 5. The connector of claim 1 in which said receptor and said arc-pinching elements are mounted in radially spaced relationship within a capsule composed of dielectric material which when exposed to an arc is non-carbon-evolving, non-tracking, and arc-suppressing, and said capsule is embedded within said non-conductive probe (c).
 6. The connector of claim 1 wherein said one of said portions is an elbow having a conductor extending through it.
 7. The combination with an electrical connector part having a conoidal exterior insulating member, of an insides embedded in said member, comprising, a female-shaped conductive element, a capsule embracing at least part of said element, said capsule being composed of dielectric material which when exposed to an arc is non-carbon-evolving, non-tracking and arc-resistant, said capsule being internally subdivided into a plurality of chambers containing respectively: i. at least part of said conductive element; and ii. paired arc-pinching elements radially biased toward each other, but free for movement into radially spaced relationship; said capsule having an axial channel open at the end thereof remote from said conductive element and extending through said chambers to accommodate movement of a conductive probe from the outer end of said member into contact with said element.
 8. The combination of claim 7 in which adjacent ones of said chambers are separated by baffles formed of arc-suppressing material.
 9. The combination of claim 7 wherein said conductive element has a surface disposed for resilient contact with said probe, and means spaced from said surface but in conductive relation with said element for diverting, away from said surface, an arc drawn between said probe and said element.
 10. An insides for a male non-conductive part of a separable electrical connector, comprising, complemental half-liners of moldable arc-resistant material, said half-liners having an axially extending valley at each end and a plurality of axially spaced partitions between said valleys, each partition having a central notch, said notches being axially aligned with each other and with said valleys, paired clappers of arc-quenching material confined between successive ones of said partitions, and means biasing the clappers of each pair toward each other.
 11. The insides of claim 10 wherein said valleys at one end of said half-liners are interlocked with a female conductive member having axially extending fingers, resilient means for radially biasing said fingers, said paired clappers having half-conical recesses addressed toward each other with their bases addressed away from said female conductive part.
 12. The insides of claim 10 having a female-configurated stationary contact at one end of said complemental half-liners.
 13. The combination with the insides of claim 12 of a removable male-configurated conductive member proportioned to be accommodated in the notches and valleys of said complemental half-liners and to be accepted by said stationary contact.
 14. The combination of claim 13 wherein the arc-accessible surface area of said clappers is substantially greater than the surface area of that portion of said male-configurated conductive member between said valleys and said stationary contact.
 15. The connector of claim 1 wherein the free end of said conductive probe is formed at least in part of arc-resisting conductive material.
 16. The connector oF claim 1 wherein said non-conductive open-ended receptor extends axially beyond the free end of said conductive probe. 